Malaysian Airlines says it now has to assume "beyond any reasonable doubt" that missing flight MH370 has been lost and and there are no survivors.
The announcement came in a text message, seen by the BBC, that was sent to families of those on board.
Malaysia Airlines light MH370, with 239 people on board, went missing after taking off from Kuala Lumpur 8 March.
Relatives have learnt the news and are wailing openly at the Lido Hotel, some unable to walk. Medical staff still bringing in stretchers— Philip Wen (@PhilipWen11) March 24, 2014
The announcement came as a search effort in the southern Indian Ocean completed a fifth day of operations.